1. Field of the Invention.
The present invention relates generally to conveyor apparatuses, and more particularly, but not by way of limitation, to a conveyor apparatus having a contact surface with a plurality of nodules formed thereon to provide a low friction surface that remains substantially free of debris.
2. Description of Related Art.
Many types of products are transported through a plant on a conveyor belt or a conveyor chain during the processing and packaging of the products. To this end, numerous types of conveyor belts and conveyor chains exist for transporting different products and accommodating the specific processing requirements of certain products. For example, flat wire belts are useful for transporting products that must be washed or dried in that water and air are able to pass freely through the wire belt. On the other hand, belts and chains with a continuous conveying surface are often used to transport meat, poultry, and beverage containers.
Particularly, when processing beverages, it is often required that the containers be backed up at certain points along the line. In these instances, the conveyor belt or chain continues to slide under the slower moving or stationary containers. A problem often encountered, however, is that the friction between the bottom of the containers and the conveying surface increases due to an increase in pressure caused by the accumulation of the containers or the gathering of debris on the conveying surface. The increased friction can result in product damage from wear on the product contact surface, deformation of flexible containers, and breakage of rigid containers due to excessive line pressure. In addition, the phenomena of "bridging" or "shingling" on containers is greatly increased with increased line pressure (friction) causing containers to lock together on the line, stopping production until a manual or mechanical unlocking occurs, and sometimes requiring the conveyor to be shut off to prevent damage to the containers.
To decrease the friction between the bottom of the containers and the conveying surface, the use of water, soap, various lubricants, or specially compounded surfactants is common on current designs of conveyor surfaces. These methods are undesirable because of the added cost to the operation and the complication of the proper disposal of the waste liquids. In addition, some container materials such as paper based laminates, and container decorations, such as labels, marking inks, and container attachments, such as instruction booklets, straws, and promotional coupons are damaged by the presence of these substances on the line. As such, most industries prefer that their conveyor systems be operated without lubricants and even without water, in other words "run dry".
Friction is also a problem in other aspects of conveying systems. For example, conveyor belts are typically supported by a platform or support assembly over which the conveyor belt slides when the conveyor belt is set in motion. Unwanted friction between the conveyor belt and the support assembly due to the collection of debris on the support assembly accelerates wear of both the belt and the support assembly and reduces the efficiency of the operation of the conveyor belt. Another area of concern is the contact which occurs between the containers being conveyed by the conveyor belt and guide rails which are often provided along the sides of the conveyor belt to guide the containers along a desired path. A reduction in friction between the sides of the containers would allow the containers to move at higher speeds with less drag which results in reduced container damage and reduced noise levels.
To this end, a need has long existed for an improved conveyor apparatus that has a low friction conveying surface and a low friction contact surface which provide a stable surface and are easy to maintain and inexpensive to manufacture and operate. It is to such an improved conveyor apparatus that the present invention is directed.